The present invention relates to steering wheels. More particularly, the present invention relates to a steering wheel comprising a ring member connected by spoke members to a boss member wherein a covering layer is integrally formed over at least a portion of the spoke members and the ring member and has an energy absorbing member embedded therein.
An example of a conventional steering wheel WO, which is disclosed in Japanese Unexamined Utility Model Publication No. 61-75372, is illustrated in FIGS. 3 and 4. The steering wheel WO comprises a boss member (B), a ring member (R) provided around the outer periphery of the boss member, spoke members (S1, S2, S3) connecting the boss member to the ring member, and a pad member (P) mounted on the boss member. Each of the spoke members includes a spoke core member (SC). A covering layer (C), made from a urethane resin, covers the outer periphery of parts of the spoke core members and the outer periphery of the entire ring member. In addition, an energy absorbing apparatus (EAA) made of a metal is disposed within a pad compartment of the pad member.
In the conventional steering wheel WO, the pad cover of the pad member is not formed integrally with the covering layer of the spoke members. Therefore, boundary lines are visible between the pad cover and the covering layer. The boundary line is a deficiency in that design.
In order to avoid that design deficiency, it would be desirable to provide a steering wheel in which a cover layer which covers the right spoke member is integrally connected to a covering layer which covers the left spoke member.
In order to achieve that object, the inventors proposed providing a covering layer for the right spoke member which is integrally formed with the covering layer for the left spoke member by connecting these layers at a point above the boss member. However, they found that it is very difficult to maintain a predetermined configuration of the connected portion of the covering layers at the point above the boss member. Further, the connected portion of the covering layers makes the space for the pad member smaller as compared to the conventional steering wheel, so that the pad member must be smaller. Consequently, the energy absorption of the energy absorbing member is reduced. This presents a significant problem.